1. Field of the Invention
The present invention relates to a reproducing apparatus for reproducing data from a record disc, on which reproduction data, such as video image, audio sound, subtitle and the like, and reproduction control data to control the reproduction of the reproduction data are recorded, such as a DVD for example.
2. Description of the Related Art
On a DVD, there are recorded not only reproduction data, such as video image, audio sound, subtitle and the like, but also reproduction control data to control the reproduction of the reproduction data. When the DVD is reproduced, a reproducing apparatus reads the reproduction control data recorded on the DVD, and uses it to specify a record position on the DVD of the reproduction data and set a reproduction order of the reproduction data for example.
The reproducing apparatus usually has a work memory for transiently storing therein a part of the reproduction control data read out from the DVD. The reproduction control data can be quickly used if the reproduction control data frequently required during the reproducing operation is stored in this work memory, in advance of actually reproducing the reproduction data by using this reproduction control data. This is because a reading speed of reading the reproduction control data from the work memory (for example, 0.1 xcexcsec) is extremely faster than a reading speed of reading the reproduction control data from the DVD (for example, 200 m sec).
By the way, a complex control is required to reproduce the DVD, in order to attain the reproduction of the video image and the audio sound rich in an interactive property. For this reason, the amount of the reproduction control data which is used for the operation for reproducing the reproduction data recorded on the DVD is very large, and is extremely large as compared with a capacity of the work memory (for example, about 1000 times). As a result, the reproduction control data, which is used after reading out from the work area during the reproducing operation, is only a part of the whole reproduction control data. Most of the reproduction control data is used after reading out from the DVD. In this way, in the reproduction of the DVD, there is a problem that the work memory cannot be effectively used. Also, this problem can be solved by increasing the capacity of the work memory. However, the increase of the capacity of the work memory brings about another problem of the increase of a cost of the reproducing apparatus. Thus, this is not desirable.
On the other hand, the usage efficiency of the work memory may be improved if the reproduction control data frequently used during the reproducing operation can be expected in advance. However, the kind or structure of the reproduction control data recorded on the DVD may be significantly changed in accordance with intention of an author or manufacturer of the DVD. Further, how to reproduce the reproduction data recorded on the DVD is variously changed depending upon the condition when a user operates the reproducing apparatus. Thus, it is difficult to expect in advance the reproduction control data frequently used during the reproducing operation.
The number of times of reading out the data from the DVD is increased if the work memory cannot be effectively used. The operation for reading out the data from the DVD involves a physical movement of an optical pickup and the like. Thus, the increase in the number of times of reading out the data from the DVD leads to the increase in a consumption power of the reproducing apparatus, and also results in a problem that a life of an optical pickup movement mechanism for moving the optical pickup is made shorter.
The present invention is proposed in view of the above mentioned problems. It is therefore an object of the present invention to provide a reproducing apparatus, which can efficiently store reproduction control data in a work memory, reduce the number of times of reading out data from a record disc, make a speed of a reproducing operation faster, drop a consumption power and make a life of an optical pickup movement mechanism longer.
The above object of the present invention can be achieved by a first reproducing apparatus provided with (i) a reading device for reading reproduction data and reproduction control data to control a reproduction of the reproduction data from a record disc, on which the reproduction data and the reproduction control data are recorded, (ii) a record medium having a plurality of memory areas, (iii) a data managing device for storing one reproduction control data read by the reading device into one of the memory areas, and (iv) a reproducing device for reproducing the reproduction data in accordance with the reproduction control data stored in the memory areas. In the first reproducing apparatus of the present invention, the data managing device is provided with: a retention priority memory for storing retention priority data, which indicate a retention priority as for each reproduction control data respectively stored in the memory areas; a selecting device for selecting one of the memory areas, into which the one reproduction control data read by the reading device is to be stored, on the basis of the retention priority data stored in the retention priority memory, when the one reproduction control data is read by the reading device; and a storing device for storing the one reproduced control data read by the reading device into the memory area selected by the selecting device.
According to the first reproducing apparatus of the present invention, when newly reading out the reproduction control data from the record disc and storing it into the record medium, the memory area in which the reproduction control data, whose retention priority is relatively low, is stored is selected as the memory area into which the newly read reproduction control data is to be stored. Then, this newly read reproduction control data is actually stored into this selected memory area. As a result, another reproduction control data which has been stored in this memory area is erased as the newly read reproduction control data replaces it. In other words, the memory area in which the reproduction control data, whose retention priority is relatively high, is stored is not selected. This implies that such reproduction control data (whose retention priority is relatively high) is maintained in the record medium as it is. This manner of selecting the memory area is performed on the basis of the retention priority data stored in the retention priority memory.
In this manner, it is possible to select the memory area while considering the usage frequency of the reproduction control data which can be expected in advance, so that it is possible to maintain the reproduction control data efficiently in the record medium.
The above object of the present invention can be also achieved by a second reproducing apparatus provided with (i) a reading device for reading reproduction data and reproduction control data to control a reproduction of the reproduction data from a record disc, on which the reproduction data and the reproduction control data are recorded, (ii) a record medium having a plurality of memory areas, (iii) a data managing device for storing one reproduction control data read by the reading device into one of the memory areas, and (iv) a reproducing device for reproducing the reproduction data in accordance with the reproduction control data stored in the memory areas. In the second reproducing apparatus of the present invention, the data managing device is provided with: a usage frequency memory for storing usage frequency data, which indicate the number of times of usage as for each reproduction control data respectively stored in the memory areas; a selecting device for selecting one of the memory areas, into which the one reproduction control data read by the reading device is to be stored, on the basis of the usage frequency data stored in the usage frequency memory, when the one reproduction control data is read by the reading device; and a storing device for storing the one reproduced control data read by the reading device into the memory area selected by the selecting device.
According to the second reproducing apparatus of the present invention, when newly reading out the reproduction control data from the record disc and storing it into the record medium, the memory area in which the reproduction control data, whose actual number of times of usage is relatively small, is stored is selected as the memory area into which the newly read reproduction control data is to be stored. Then, this newly read reproduction control data is actually stored into this selected memory area. As a result, another reproduction control data which has been stored in this memory area is erased as the newly read reproduction control data replaces it. In other words, the memory area in which the reproduction control data, whose actual number of times of usage is relatively large, is stored is not selected. This implies that such reproduction control data (whose actual number of times of usage is relatively large) is maintained in the record medium as it is. This manner of selecting the memory area is performed on the basis of usage frequency data stored in the retention priority memory.
In this manner, it is possible to select the memory area while considering the actual usage frequency of the reproduction control data (which may not be expected in advance), so that it is possible to maintain the reproduction control data efficiently in the record medium.
The above object of the present invention can be also achieved by a third reproducing apparatus provided with (i) a reading device for reading reproduction data and reproduction control data to control a reproduction of the reproduction data from a record disc, on which the reproduction data and the reproduction control data are recorded, (ii) a record medium having a plurality of memory areas, (iii) a data managing device for storing one reproduction control data read by the reading device into one of the memory areas, and (iv) a reproducing device for reproducing the reproduction data in accordance with the reproduction control data stored in the memory areas. In the third reproducing apparatus of the present invention, the data managing device is provided with: a retention priority memory for storing retention priority data, which indicate a retention priority as for each reproduction control data respectively stored in the memory areas; a usage frequency memory for storing usage frequency data, which indicate the number of times of usage as for each reproduction control data respectively stored in the memory areas; a selecting device for selecting one of the memory areas, into which the one reproduction control data read by the reading device is to be stored, on the basis of the retention priority data stored in the retention priority memory and the usage frequency data stored in the usage frequency memory, when the one reproduction control data is read by the reading device; and a storing device for storing the one reproduced control data read by the reading device into the memory area selected by the selecting device.
According to the third reproducing apparatus of the present invention, when newly reading out the reproduction control data from the record disc and storing it into the record medium, the memory area in which the reproduction control data, whose retention priority is relatively low and whose actual number of times of usage is relatively small, is stored is selected as the memory area into which the newly read reproduction control data is to be stored. Then, this newly read reproduction control data is actually stored into this selected memory area. As a result, another reproduction control data which has been stored in this memory area is erased as the newly read reproduction control data replaces it. In other words, the memory area in which the reproduction control data, whose retention priority is relatively high or whose actual number of times of usage is relatively large, is stored is not selected. This implies that such reproduction control data (whose retention priority is relatively high or whose actual number of times of usage is relatively large) is maintained in the record medium as it is. This manner of selecting the memory area is performed on the basis of the retention priority data stored in the retention priority memory and the usage frequency data stored in the retention priority memory.
In this manner, it is possible to select the memory area while considering the usage frequency of the reproduction control data which can be expected in advance and the actual usage frequency of the reproduction control data (which may not be expected in advance), so that it is possible to maintain the reproduction control data efficiently in the record medium. Especially, since the memory area is selected with considering the actual number of times of usage, even if it is difficult to expect the usage frequency of the reproduction control data in advance, it is possible to maintain the reproduction control data efficiently in the record medium.
In one aspect of the third reproducing apparatus of the present invention, the selecting device selects one of the memory areas, in which the reproduction control data corresponding to the lowest retention priority is stored, on the basis of the retention priority data stored in the retention priority memory, and if more than one memory areas are selected on the basis of the retention priority data, the selecting device further selects one of the selected more than one memory areas, in which the reproduction control data corresponding to the smallest number of times of usage is stored, on the basis of the usage frequency data stored in the usage frequency memory.
According to this aspect, when storing the newly read reproduction control data into the record medium, the memory area in which the reproduction control data, whose retention priority is the lowest and whose actual number of times of usage is the smallest, is stored is selected as the memory area into which the newly read reproduction control data is to be stored. Therefore, it is possible to maintain the reproduction control data efficiently in the record medium.
In one aspect of the first reproducing apparatus or another aspect of the third reproducing apparatus of the present invention, the data managing device is further provided with: a priority judging device for judging the retention priority as for the one reproduction control data when the one reproduction control data is stored into the memory area selected by the selecting device; and an updating device for updating the retention priority data stored in the retention priority memory in accordance with the retention priority judged by the priority judging device.
According to this aspect, each time when the reproduction control data read out from the record disc is stored into the selected memory area, the retention priority data is appropriately updated.
In this aspect, the reproduction data may be recorded on the record disc in such a condition that the reproduction data is divided into a plurality of blocks, and the priority judging device judges that the retention priority of the reproduction control data indicating a record position of a block of the reproduction data, is higher than that not-indicating the record position.
In this case, it is possible to maintain the reproduction control data, which indicates the record position of the block on the record disc, in the record medium for a long period of time. The reproduction control data indicating the record position of the block on the record disc is frequently used during the reproducing operation in the reproducing apparatus. Therefore, by maintaining such reproduction control data in the record medium for a long period of time, it is possible to always speedily read out such reproduction control data without performing the disc reading operation.
In one aspect of the second reproducing apparatus or another aspect of the third reproducing apparatus of the present invention, the data managing device is further provided with: an initializing device for initializing the number of times of usage as for the one reproduction control data when the one reproduction control data is stored into the memory area selected by the selecting device; and an incrementing device for incrementing the number of times of usage in the usage frequency data stored in the usage frequency memory each time when respective one reproduction control data stored in the memory areas is used.
According to this aspect, each time when the reproduction control data read out from the record disc is stored into the selected memory area, it is possible to initialize the number of times of usage corresponding to this memory area appropriately. Further, it is possible to accurately count the number of times of usage of the reproduction control data stored in this memory area, so that it is possible to accurately store this incremented result as the number of times of usage.
In another aspect of the first, second or third reproducing apparatus of the present invention, a data reading speed of the record medium is faster that that of the record disc.
According to this aspect, it is possible to make the reproducing operation in the reproducing apparatus faster, by maintaining the reproduction control data, whose usage frequency is high, efficiently in the record medium.
In another aspect of the first, second or third reproducing apparatus of the present invention, the record medium comprises a work memory used when an error correction process is performed onto data groups including the reproduction data and the reproduction control data.
According to this aspect, in case that the reproduction control data, whose usage frequency expected in advance is high or the actual number of times of usage is large, is included in a data group onto which the error correction process is performed, it is possible to maintain this data group in the work memory for a ling period of time. Therefore, it is possible to speedily read out the reproduction control data, which is frequently used, from the work memory without performing the disc reading operation.
In another aspect of the first, second or third reproducing apparatus of the present invention, the record medium comprises a work memory used when the reproducing device is controlled by a controller in accordance with the reproduction control data.
According to this aspect, it is possible to maintain the reproduction control data, which is frequently used in the reproducing operation by the controller, in the work memory for a ling period of time. Therefore, it is possible to speedily read out the reproduction control data, which is frequently used, from the work memory without performing the disc reading operation.
In another aspect of the first, second or third reproducing apparatus of the present invention, the record medium comprises a first work memory used when an error correction process is performed onto data groups including the reproduction data and the reproduction control data, and a second work memory used when the reproducing device is controlled by a controller in accordance with the reproduction control data, and the data managing device stores the one reproduction control data into one of the memory areas in the first work memory and into one of the memory areas in the second work memory, independently from each other.
According to this aspect, it is possible to maintain a plurality of the reproduction control data, in the first and second work memories respectively for a ling period of time. Therefore, it is possible to speedily read out the reproduction control data, which is frequently used, from the first or second work memory without performing the disc reading operation. As a result, the reproducing operation speed is drastically increased, and the number of times of disc reading is drastically decreased.